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Extraction of bioactive substances from black chokeberry pomace
Kapiton, Ulyana ; Veselá, Mária (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with the quantification of selected bioactive substances in chokeberry juices, in the extracts of chokeberry and in chokeberry tea. In the theoretical part, there is a botanical description of chokeberry, (Aronia melanocarpa). Furthermore, the chemical properties of aronia and their use in the food, cosmetics industry and in the medicine. At the end of the theoretical part there are presented manual methods for determination of simple saccharides and briefly described selected extraction methods. The experimental part contains the determination of these chemical characteristics of analyzed aronia products: pH, titratable acidity, refractometric determination of dry matter, reducing sugars according to Bertrand's method and gravimetric determination, total phenolics and total anthocyanins. The highest phenolic content 319,54 mg·dm-3 were determined in a sample of aronia tea for 10 min digestion. The highest concentration of anthocyanin dyes was also determined in this tea – 889,49 mg·dm-3.
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Study of extraction of the biologically active substances from elderberry marc
Lošková, Tereza ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with the determining of anthocyanin pigments in the extracts of elderberry marc (Sambucus nigra L.). The theoretical part is divided into four main chapters. In the first chapter there is botanical characteristics of elderberry, its origin and occurrence, chemical composition and the possibilities of usage in a food industry. The second part is devoted to characterization of phenolic compounds in berry fruits. Bigger attention is given to anthocyanin dyes, its occurrence, properties, health and antioxidant effects and the possibilities of usage in food industry. The third chapter is devoted to methods of determination of discussed dyes and phenolic compounds. The fourth chapter deals with the possibilities of disruption of plant cell walls. In the experimental part a series of elderberry marc's extraction was made. The purpose was to optimize the extraction course and to get the highest yield of dyes in an economically and operationally acceptable way. Time dependence of extractions was studied and a kind of extraction solvent and a ratio of its components were optimized. Distilled water or its mixture with ethanol was used as a solvent. During the water extraction the temperatures 25 °C and 50 °C were maintained and with the higher temperature the higher yields were obtained. Apart from this another supporting components as cellulolytic enzyme, ultrasound or shaker were used. The most effective method of extraction proved to be the extraction by the mixture water-ethanol (50:50) in the volume 80 mL. The total anthocyanins yield of this extraction was, expressed as cyanidin-3-glucoside equivalent, 914,4 ± 3,8 mg100 g-1 dry weight after 10 hours and the total phenolics yield was, expressed as gallic acid equivalent, 1957,0 ± 9,9 mg100 g-1 dry weight at the same time. The usage of ultrasound increased the efficiency of the extraction by water at 50 °C by 12 %. On the contrary, the usage of cellulolytic enzyme didn't increase the anthocyanin yield, because the enzyme was inactive.
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